Chemical mechanical polishing conditioner

ABSTRACT

The present invention relates to a chemical mechanical polishing conditioner, comprising: a substrate; a binding layer disposed on the substrate; and multiple abrasive units placed on the binding layer; wherein each abrasive unit has an abrasive unit substrate and an abrasive layer which is a diamond film formed by chemical vapor deposition and has multiple abrasive tips; wherein the abrasive units have uniform heights, such that the abrasive units form a planarized surface. Therefore, the present invention can improve planarization of the conditioner, enhance efficiency, and prolong lifetime.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a chemical mechanical polishingconditioner, especially to a combinational chemical mechanical polishingconditioner having tips of leveling heights.

2. Description of the Prior Art(s)

Chemical Mechanical Polishing (abbreviated as CMP) is commonly used invarious industries to polish the surfaces of various articles made ofceramic, silicon, glass, quartz, or metal. With the applicability oflarge-scaled planarization of integrated semiconductor device, CMPbecomes a common planarization technique in the semiconductor process.

During the CMP process of the semiconductor, a pad is contacted with awafer or other semiconductor elements in conjunction with suitableabrasive slurry to remove impurities or protruding structures on thesurface of the wafer through both chemical reaction and mechanicalforce. When the pad has been used for a period of time, polishing debrisproduced from the CMP process will accumulate and stagnate on thesurface of the pad, thereby reducing the polishing effect andefficiency. Therefore, a chemical mechanical polishing conditioner canbe used to dress the surface of the pad for the desired polishing effectand efficiency.

In the preparation of a chemical mechanical polishing conditioner(abbreviated as CMP conditioner), multiple abrasive particles aremounted to a binding layer to form an abrasive layer. The abrasive layeris fixed to a surface of a substrate by brazing or sintering. Said CMPconditioner is suitable for dressing the pads; however, in moresophisticated semiconductor process with line-width below 45 nanometers,the rough surface of the pad that is too coarse will cause problems suchas scratch, local over-polishing, depression, or non-uniform thicknessof the wafer. As the line-width of integrated semiconductor device isdecreasing, the demand for the planarization of the surface of the waferis increasing, and same for the CMP conditioner.

Taiwan Patent Application Publication No. 201341113 discloses acombinational chemical mechanical polishing conditioner comprising asubstrate; multiple abrasive units disposed on a surface of thesubstrate and each abrasive unit comprising multiple abrasive tips and abinder layer fixing the abrasive tips; a thickness-adjustable adhesivelayer to fix the abrasive units on the surface of the substrate. Aheight difference between a first highest point and a second highestpoint of a predetermined plane is less than 10 micrometers. A heightdifference between the first highest point and a tenth highest point ofthe predetermined plane is less than 20 micrometers. A height differencebetween the first highest point and a hundredth highest point of thepredetermined plane is less than 40 micrometers. The first highest pointof the predetermined plane protrudes more than 50 micrometers away fromthe binder layer. This prior invention also relates to the method forpreparing the combined chemical mechanical polishing conditioner and theapplications of the combinational chemical mechanical polishingconditioner.

Taiwan Patent Application Publication No. 201249595 discloses a padconditioner for CMP comprising a substrate having a first set ofprotrusions and a second set of protrusions. The first set of theprotrusions has a first average height and the second set of theprotrusions has a second average height. The first average height andthe second average height are different. Tops of the protrusions of thefirst set of the protrusions have protruding surfaces. Tops of theprotrusions of the second set of the protrusions have non-flat surfaces.A layer of polycrystalline diamond is disposed on each non-flat surfaceof the first set of the protrusions and the second set of theprotrusions. The protrusions can be discriminated by their heights,predetermined positions, or dimensions of substrates. This priorinvention provides various ways to measure the protrusions including anaverage height measured from a back side of the pad conditioner for CMP,a peak-to-valley height, or a protruding height. However, theprotrusions and the substrate are integrated and cannot form a totallyplanarized surface to improve the abrasive efficiency and prolonglifetime of the CMP conditioner.

Taiwan Patent Application Publication No. 201341113 discloses a padconditioner with a uniform height design. However, said invention isdifferent from the present invention to be mentioned afterward in thestructure of CMP conditioner.

To overcome the shortcomings, the present invention provides a CMPconditioner to mitigate or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

The major objective of the present invention is to provide a CMPconditioner by combining abrasive units in smaller dimensions with asubstrate in larger dimensions to provide a planarized surface. Theplanarized surface can improve the polishing effect of the CMPconditioner.

To achieve the abovementioned objective, the present invention providesa CMP conditioner. The CMP conditioner comprises a substrate, a bindinglayer disposed on the substrate, and multiple abrasive units placed onthe binding layer. Each abrasive unit has an abrasive layer and anabrasive unit substrate. The abrasive layer is a diamond film formed bychemical vapor deposition and has multiple abrasive tips. Heights of theabrasive units are equal to make the CMP conditioner have a planarizedsurface. Preferably, the CMP conditioner has the abrasive units of equalthicknesses and the binding layer of a fixed thickness to form theplanarized surface. Alternatively, the CMP conditioner has the abrasiveunits having partially equal or different thicknesses and the bindinglayer of various thicknesses, thereby matching the abrasive units ofdifferent thicknesses to form the planarized surface.

The heights of the abrasive units of the present invention are equal.However, due to the slight precision error during the manufacturingprocess, a height difference between any two of the abrasive unitspossibly exists. The height difference between any two of the abrasiveunits is less than 20 micrometers, preferably 10 micrometers, which canbe achieved by controlling the manufacturing process.

Shape of the abrasive tips of the present invention can be customized bythe need of users or the polishing condition. The abrasive tips are inthe shape of, but not limited to, knife edges, cones, arcs, cylinders,pyramids, or prisms. Preferably, the abrasive tips are in the shape ofpyramids. Alternatively, the abrasive tips are in the shape of prisms.Alternatively, the abrasive tips are cylindrical in shape.

Alignment directions or tip angles of the abrasive tips of the presentinvention can be customized by the need of users or the polishingcondition. The alignment directions of the abrasive tip are uniform,partially uniform, or different. Preferably, the abrasive tips areperpendicular to a pad. Alternatively, the abrasive tips arenon-perpendicular to the pad.

The tip angles of the abrasive tip are equal, partially equal, ordifferent. Preferably, the tip angles of the abrasive tips are 60degrees, 90 degrees, or 120 degrees. Alternatively, the tip angles ofsome of the abrasive tips are 60 degrees and the tip angles of the otherabrasive tips are 90 degrees.

Besides, horizontal distances between any two neighboring abrasive tipsof the present invention can be customized by the need of users or thepolishing condition. The horizontal distances between any twoneighboring abrasive tips are equal, partially equal, or different.Preferably, the horizontal distances between any two neighboringabrasive tips are 1.5 times, 2 times, or 3 times larger than an outerdiameter of the abrasive tips. Alternatively, some of the horizontaldistances between any two neighboring abrasive tips are 2 times largerthan the outer diameter of the abrasive tips and the other of thehorizontal distances between any two neighboring abrasive tips are 3times larger than the outer diameter of the abrasive tips.

A thickness of the substrate of the present invention and thethicknesses of the abrasive units can be customized by the need of usersor the polishing condition. The thickness of the substrate ranges from10 millimeters (abbreviated as mm) to 200 mm. Preferably, the thicknessof the substrate ranges from 60 mm to 100 mm. More preferably, thethickness of the substrate is 80 mm. The thicknesses of the abrasiveunits are equal, partially equal, or different. Preferably, thethicknesses of the abrasive units range from 5 mm to 100 mm. Morepreferably, the thicknesses of the abrasive units range from 15 mm to 30mm. In the best condition, the thicknesses of the abrasive units are 20mm.

Preferably, a middle layer is disposed between the abrasive layer andthe abrasive unit substrate. The middle layer is made of the groupconsisting of aluminum oxide, silicon carbide, and aluminum nitride.More preferably, the middle layer is silicon carbide.

The middle layer of the present invention can be formed by, but is notlimited to, chemical vapor deposition, physical vapor deposition,soldering, or brazing.

The abrasive layer of the present invention is made of monocrystallinediamond or polycrystalline diamond. Preferably, the abrasive layer ismade of polycrystalline diamond and a crystal dimension of the abrasivelayer ranges from 5 nanometers to 50 micrometers. More preferably, thecrystal dimension of the abrasive layer ranges from 10 nanometers to 20micrometers. The abrasive unit substrate of the present invention is aconductive substrate or an insulating substrate. The conductivesubstrate is made of molybdenum, tungsten, or tungsten carbide. Apatterned surface with multiple surface tips can be formed on theconductive substrate by electric discharge machining and the abrasivelayer are successively formed on the surface tips by chemical vapordeposition to obtain the abrasive tips. Alternatively, a patternedsurface with multiple surface tips can be formed on the insulatingsubstrate by mechanical polishing or laser processing, and the abrasivelayer are successively formed on the surface tips by chemical vapordeposition to obtain the abrasive tips. Alternatively, a surface of theabrasive unit substrate is flat. The abrasive layer is deposited on theabrasive unit substrate by chemical vapor deposition and has multipleabrasive tips. The insulating substrate is made of ceramic material ormonocrystalline material. Preferably, the ceramic material is siliconcarbide. The monocrystalline material is silicon or aluminum oxide.

The binding layer of the present invention can be customized by the needof users or the polishing condition. The binding layer is made of, butnot limited to, ceramic material, brazing material, electroplatingmaterial, metallic material, or polymeric material. Preferably, thebinding layer is made of brazing material. The brazing material is madeof the group consisting of iron, cobalt, nickel, chromium, manganese,silicon, aluminum, or any combination thereof. Alternatively, thebinding layer is made of polymeric material. The polymeric material isepoxy resin, polyester resin, polyacrylate resin, or phenol resin.

A component or a dimension of the substrate of the present invention canbe customized by the need of users or the polishing condition. Thesubstrate is stainless steel substrate, die steel substrate, metal alloysubstrate, ceramic substrate, plastic substrate, or any combinationthereof. Preferably, the substrate is stainless steel substrate.

Preferably, the substrate is a flat substrate or a notch substrate. Morepreferably, the substrate is the flat substrate. Alternatively, thesubstrate is the notch substrate.

The polishing effect of the CMP conditioner of present invention isachieved by using the abrasive units of equal thicknesses and thebinding layer of a fixed thickness to form the planarized surface, orusing the abrasive units having partially equal or totally differentthicknesses and the binding layer with various thicknesses, therebymatching the abrasive units of different thicknesses to form theplanarized surface. The planarized surface can improve the polishingeffect of the CMP conditioner.

Other objectives, advantages and novel features of the invention willbecome more apparent from the following detailed description when takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a CMP conditioner in accordance with Embodiment1 of the present invention;

FIG. 2 is a side view of a CMP conditioner in accordance with Embodiment2 of the present invention;

FIG. 3 is a top view of a CMP conditioner in accordance with Embodiment1 of the present invention;

FIG. 4A is a top view of an abrasive unit of a CMP conditioner inaccordance with Embodiment 1 of the present invention;

FIG. 4B is a top view of an abrasive unit of a CMP conditioner inaccordance with Embodiment 3 of the present invention; and

FIG. 4C is a top view of an abrasive unit of a CMP conditioner inaccordance with Embodiment 4 of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1

With reference to FIG. 1, the present invention provides a chemicalmechanical polishing conditioner 1. The chemical mechanical polishingconditioner 1 comprises a substrate 10, a binding layer 11, and multipleabrasive units 12. The substrate 10 is made of stainless steel. Thesubstrate 10 is a flat substrate and has a thickness of 80 mm. Thebinding layer 11 is disposed on the substrate 10. The abrasive units 12are annularly placed on the binding layer 11; in other words, theabrasive units 12 are fixed on the substrate 10 via the binding layer11. Thicknesses of the abrasive units 12 are equal. Each abrasive unit12 has an abrasive unit substrate 13 and an abrasive layer 14. Theabrasive unit substrate 13 is a ceramic substrate made of siliconcarbide. A surface of the abrasive unit substrate 13 is a patternedsurface with multiple surface tips, and the abrasive layer 14 issuccessively formed on the surface tips by chemical vapor deposition toobtain abrasive tips. The abrasive tips are in the shape of pyramids.Specifically, with reference to FIG. 4A, the abrasive tips arecontinuously arranged on the abrasive unit substrate 13 with an arraypattern. The abrasive tips are in the shape of quadrangular pyramids.Alignment directions of the abrasive tips are uniform. Tip angles of theabrasive tips are equal. The abrasive units 12 are fixed on thesubstrate 10 through the binding layer 11. In addition, heights of theabrasive units 12 are equal to make the chemical mechanical polishingconditioner 1 have a planarized surface. Due to the slight precisionerror during manufacturing process, a height difference between any twoof the abrasive units 12 is less than 10 micrometers.

With reference to FIG. 3, the abrasive units 12 with equal heights areon the substrate 10 and the binding layer 11. Each abrasive unit 12comprises the abrasive unit substrate 13 and the abrasive layer 14. Theabrasive tips are in the shape of pyramids. Besides, the abrasive units12 are annularly placed on the binding layer 11. Said height of theabrasive units 12 is the shortest distance between the abrasive tip anda bottom surface of the substrate 10. Said thickness of the abrasiveunits 12 is the shortest distance between the abrasive tip and a bottomsurface of the abrasive unit substrate 13.

Embodiment 2

With reference to FIG. 2, the CMP conditioner in Embodiment 2 is similarwith the CMP conditioner in Embodiment 1. The difference between the twoembodiments is that the thicknesses of the abrasive units 22 ofEmbodiment 2 are partially equal. The heights of the abrasive unit 22are still equal; that is to say, the chemical mechanical polishingconditioner also has a planarized surface. The planarized surface isachieved by controlling a thickness of the binding layer 21 to match theabrasive units 22 having partially equal thicknesses.

The CMP conditioner of the present embodiment comprises the substrate20, the binding layer 21, and the abrasive units 22. The substrate 20 ismade of stainless steel. The substrate 20 is a flat substrate and has athickness of 80 mm. The binding layer 21 is disposed on the substrate20. The abrasive units 22 are placed on the binding layer 21; in otherwords, the abrasive units 22 are fixed on the substrate 20 through thebinding layer 21. The abrasive unit substrate 23 is a ceramic substratemade of silicon carbide. The abrasive unit substrates 23 have twodifferent thicknesses, 20 mm and 30 mm. The surface of the abrasive unitsubstrate 23 is flat. The abrasive layer 24 is deposited on the abrasiveunit substrate 23 by chemical vapor deposition. The abrasive layer 24has the abrasive tips. The abrasive tips are in the shape of pyramids,more specifically, quadrangular pyramids (such as FIG. 4A). The abrasivetips are continuously arranged on the abrasive unit substrate 23 with anarray pattern. The alignment directions of the abrasive tips areuniform. The tip angles of the abrasive tip are equal. The abrasiveunits 22 are fixed on the substrate 20 through the binding layer 21. Theplanarized surface of the chemical mechanical polishing conditioner isachieved by controlling the binding layer 21 to match the abrasive units22.

Embodiment 3

The CMP conditioner in Embodiment 3 is similar to the CMP conditioner inEmbodiment 1. The difference between the two embodiments is that theabrasive tips of the CMP conditioner in Embodiment 1 are in the shape ofpyramids and the abrasive tips of the CMP conditioner in Embodiment 3are in different shape to the abrasive tips of the CMP conditioner inEmbodiment 1.

With reference to FIG. 4A, the abrasive tips of the CMP conditioner inEmbodiment 1 are in the shape of pyramids and the abrasive tips arecontinuously arranged on the abrasive unit substrate 13 with an arraypattern. With reference to FIG. 4B, the abrasive tips 35 of Embodiment 3are in the shape of prisms, specifically, quadrangle prism. The abrasivetips 35 of the abrasive layer 34 are continuously arranged on theabrasive unit substrate 33 with an array pattern.

Embodiment 4

The CMP conditioner in Embodiment 4 is similar to the CMP conditioner inEmbodiment 1. The difference between the two embodiments is that theabrasive tips of the CMP conditioner in Embodiment 1 are in the shape ofpyramids and the abrasive tips of the CMP conditioner in Embodiment 3are in different shape to the abrasive tips of the CMP conditioner inEmbodiment 1.

With reference to FIG. 4A, the abrasive tips of the CMP conditioner inEmbodiment 1 are in the shape of pyramids and the abrasive tips arecontinuously arranged on the abrasive unit substrate 13 with an arraypattern. With reference to FIG. 4C, the abrasive tips 45 of Embodiment 4are cylindrical in shape. The abrasive tips 45 of the abrasive layer 44are continuously arranged on the abrasive unit substrate 43 with anarray pattern.

Even though numerous characteristics and advantages of the presentinvention have been set forth in the foregoing description, togetherwith details of the structure and features of the invention, thedisclosure is illustrative only. Changes may be made in the details,especially in matters of shape, size, and arrangement of parts withinthe principles of the invention to the full extent indicated by thebroad general meaning of the terms in which the appended claims areexpressed.

What is claimed is:
 1. A chemical mechanical polishing conditionercomprising: a substrate; a binding layer disposed on the substrate; andmultiple abrasive units placed on the binding layer, each abrasive unithaving an abrasive layer and an abrasive unit substrate, the abrasivelayer being a diamond film formed by a chemical vapor deposition andhaving multiple abrasive tips; wherein heights of the abrasive units areequal to form a planarized surface.
 2. The chemical mechanical polishingconditioner as claimed in claim 1, wherein a height difference betweenany two of the abrasive units is less than 20 micrometers.
 3. Thechemical mechanical polishing conditioner as claimed in claim 1, whereinthe abrasive tips are in the shape of knife edges, cones, arcs,cylinders, pyramids, or prisms.
 4. The chemical mechanical polishingconditioner as claimed in claim 1, wherein alignment directions of theabrasive tips are uniform, partially uniform, or different.
 5. Thechemical mechanical polishing conditioner as claimed in claim 1, whereintip angles of the abrasive tips are equal, partially equal, ordifferent.
 6. The chemical mechanical polishing conditioner as claimedin claim 1, wherein horizontal distances between any two neighboringabrasive tips are equal, partially equal, or different.
 7. The chemicalmechanical polishing conditioner as claimed in claim 1, whereinthicknesses of the abrasive units are equal, partially equal, ordifferent.
 8. The chemical mechanical polishing conditioner as claimedin claim 1, wherein a middle layer is disposed between the abrasivelayer and the abrasive unit substrate.
 9. The chemical mechanicalpolishing conditioner as claimed in claim 8, wherein the middle layer ismade of the group consisting of aluminum oxide, silicon carbide, andaluminum nitride.
 10. The chemical mechanical polishing conditioner asclaimed in claim 1, wherein the abrasive unit substrate is a conductivesubstrate or an insulating substrate.
 11. The chemical mechanicalpolishing conditioner as claimed in claim 1, wherein the binding layeris made of a ceramic material, a brazing material, a electroplatingmaterial, a metallic material, or a polymeric material.
 12. The chemicalmechanical polishing conditioner as claimed in claim 11, wherein thepolymeric material is epoxy resin, polyester resin, polyacrylate resin,or phenol resin.
 13. The chemical mechanical polishing conditioner asclaimed in claim 11, wherein the brazing material is made of a groupconsisting of iron, cobalt, nickel, chromium, manganese, silicon,aluminum, and any combination thereof.
 14. The chemical mechanicalpolishing conditioner as claimed in claim 1, wherein the substrate is astainless steel substrate, a die steel substrate, a metal alloysubstrate, a ceramic substrate, a plastic substrate, or any combinationthereof.
 15. The chemical mechanical polishing conditioner as claimed inclaim 1, wherein the substrate is a flat substrate or a notch substrate.